The subject application provides a method and system for processing soap and soap-like materials.
As anyone who has ever fallen on a bar of soap will attest, soap which sinks to the bottom of the bathtub presents an unseen safety hazard. Moreover, for underdeveloped countries and people who revel in the outdoors, floating soap offers the only satisfactory medium for bathing in a stream, lake or river. Accordingly, it is an object of subject invention to provide a means for producing floating soap and soap-like materials.
Although there has long been a need for water buoyant soaps, methods for their production have typically been limited to batch processes, progressive compacting or chemical induction of gas. The subject invention overcomes these limitations by providing a continuous flow system which affords advantages not contemplated in the past.
In the manufacture of water-buoyant soap, air is entrapped within the soap to lower its specific gravity to a value less than 1.0. To aid in understanding the objects, features and advantages of the subject invention, a brief history of floating soap will be chronicled.
An early method of producing water buoyant milled soap is described by Hood, U.S. Pat. No. 2,210,824, issued Aug. 13, 1940, the contents of which are herein incorporated by reference. In this method, air introduced into a batch of soap is expanded under vacuum (by the withdrawing a piston in a hermetically sealed container), thus creating a soap that is lighter than water.
Westerberg, U.S. Pat. No. 2,360,920, issued Oct. 24, 1944, the contents of which are herein incorporated by reference, teaches a batch method of making soap which is light, airy and suitable for single use. To obtain such an article, a soap and water solution is formed and then heated to a temperature of approximately 65.degree. C. The mixture is then beaten until it reaches a frothy consistency which will hold its body, thereby producing a low weight soap.
Bodman, U.S. Pat. No. 2,398,776, issued Apr. 23, 1946, the contents of which are herein incorporated by reference, teaches a batch method of producing an aerated soap. In this method, molten soap is introduced under pressure into a Banbury mixer having rotating spiral blades. The action of the blades upon the pressurized soap causes air to be evenly dispersed throughout. After the soap is thoroughly aerated, it is released into a form-imparting means, from which the solidified mass can be removed and cut into cakes or bars.
Marshall, U.S. Pat. No. 2,494,891, issued Jan. 17, 1950, the contents of which are herein incorporated by reference, teaches a method and apparatus for making floating soap. In this method, a milled soap mass is plodded and extruded into very fine diameter threads while regulating air pressure. The shredded soap mass is then compacted progressively so as to become hard without allowing the escape of occluded air.
Dupuis, U.S. Pat. No. 3,413,230, issued Nov. 26, 1958, the contents of which are herein incorporated by reference, describes a method in which a hollow body containing entrapped air is placed within the soap bar so as to cause the entire bar to float.
Susuki, et al., U.S. Pat. No. 3,649,545, issued Mar. 14, 1972, the contents of which are herein incorporated by reference, teach a synthetic detergent mass and method of manufacture. The detergent can be made to float by using hollow areas within the detergent mass or by using a foaming agent generated within the slurry, i.e., a chemically induced gas.
Another object of this invention is to provide a method of processing a soap or soap-like material without the milling required in the production of high quality hard soaps. In brief, milling involves extruding or comminuting "kettle soap" which has previously been cooled. The diminutive pieces of cool kettle soap are then compressed to form a hard soap. By mixing and cooling the soap, in sequence or concurrently, the subject invention eliminates milling.
Of general interest is a series of patents to Clarke, et al. (U.S. Pat. Nos. 4,479,884, 4,517,107, 4,680,132, issued Oct. 30, 1984, May 14, 1985 and Jul. 14, 1987, respectively), the contents of which are herein incorporated by reference, which teach detergent bars and methods for making the same. In the Clarke, et al. methodology, material is forced through a mixer which moves the material through cavities alternately on opposing faces of the stator and rotor. Although floating soap is not produced by this process, these patents illustrate mixer technology in the extended field of soap production.
Objects of this application include providing a method and system for processing soap and soap-like materials. Further objects include producing a floating soap, and in particular a soap having a white color, and minimizing loss of expensive fragrance. It is therefore a feature of the subject invention to provide a continuous flow system and a further feature to use injected gas to facilitate gas incorporation to form a floating soap. Yet another feature is the use of a closed system.
Through these objects and features, the subject invention offers the advantages of eliminating the need for milling, providing a floating soap having uniform gas distribution, creating a floating soap having a white color without the use of dyes or oxidants, minimizing the loss of volatiles (such as fragrances) and affording a rapid and continuous method for manufacturing high quality soap.